The following relates generally to memory devices and more specifically to techniques for concurrently accessing memory cells within independent sections of a memory array.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary devices have two states, often denoted by a logic “1” or a logic “0.” In other systems, more than two states may be stored. To access the stored information, the electronic device may read, or sense, the stored state in the memory device. To store information, the electronic device may write, or program, the state in the memory device.
Multiple types of memory devices exist, including random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, and others. Memory devices may be volatile or non-volatile. Non-volatile memory, e.g., flash memory, can store data for extended periods of time even in the absence of an external power source. Volatile memory devices, e.g., DRAM, may lose their stored state over time unless they are periodically refreshed by an external power source. A binary memory device may, for example, include a charged or discharged capacitor. A charged capacitor may become discharged over time through leakage currents, resulting in the loss of the stored information. Certain aspects of volatile memory may offer performance advantages, such as faster read or write speeds, while aspects of non-volatile, such as the ability to store data without periodic refreshing, may be advantageous.
FeRAM may use similar device architectures as volatile memory but may have non-volatile properties due to the use of a ferroelectric capacitor as a storage device. FeRAM devices may thus have improved performance compared to other non-volatile and volatile memory devices. In FeRAM devices, a higher voltage may be applied to polarize a memory cell than would be applied in a volatile RAM memory cell (e.g., a DRAM cell with a dielectric capacitor), due to the ferroelectric capacitor having relatively high voltages for polarization. Such higher voltages may result in relatively longer times for polarizing the memory cell due to increased times to charge to such a higher voltage (e.g., via charge pumping). In order to mitigate such relatively high voltages, some designs may move a plate voltage associated with a memory cell in an opposite direction as a voltage at a digit line of the memory cell, thus creating a polarization bias that may be used to operate the cell. However, such movement of the plate voltage causes a bifurcated writeback of ones and zeros to cells, as logical “zeros” are written when the plate voltage is high, and logical “zeros” are written when the plate voltage is low. Such a bifurcated writeback may also increase times for writing to a memory relative to volatile RAM, thus increasing average access times for a memory. Accordingly, techniques for reducing access times may enhance the performance of nonvolatile FeRAM devices.